Tetrasilicic esters and their use for textile treatment



United States Int. Cl. cine 7/04 US. Cl. 260448.8 2 Claims ABSTRACT OFTHE DISCLOSURE A new tetrasilicic ester of at least one unsaturatedlongchain fatty alcohol or mixture of fatty alcohols which has an iodinenumber of at least 40, and a method of treating textiles in which thetextiles are impregnated with the new tetrasilicic ester, preferably inthe form of an aqueous emulsion, and if necessary then dried.

It is known that textile materials may be treated with tetrasilicicesters of saturated long-chain fatty alcohols. Such a treatment mayserve for example to make the material being treated water-repellent orto improve the resistance to abrasion of crease-resist finishedmaterial. These prior art agents have a number of disadvantages. Whenthey have been derived from linear alcohols, they are hard and rigid atroom temperature and impart an unpleasant harsh handle to the textilematerial. When they have been derived from branched alcohols, althoughthey are usually liquid at room temperature they have a very unpleasantodor which adheres firmly to the material treated therewith.

It is an object of this invention to provide an improved method oftreating textiles with tetrasilicic esters which not only improves theabrasion resistance, tear resistance and sewing properties of thetreated textiles but also imparts a pleasant soft handle thereto.

Another object of the invention is to provide an improved process fortreating textiles with tetrasilicic esters which does not impart anyunpleasant odor to the textiles.

It is moreover an object of the invention to provide aqueous emulsionsof tetrasilicic esters which can be used as textile treating agents andare distinguished by particularly good stability in storage.

Finally it is an object of this invention to provide new tetrasilicicesters having valuable properties, which have a liquid to pastyconsistency at room temperature and are free from unpleasant odor.

These and other objects are achieved by new tetrasilicic esters whichare derived from at least one long-chain unsaturated fatty alcohol or amixture having an iodine number of at least 40 of at least onelong-chain unsaturated fatty alcohol and at least one long-chainsaturated fatty alcohol.

The new tetrasilicic esters are eminently suitable as textile treatingagents.

In the present specification, long-chain means containing at leasttwelve carbon atoms; tetrasilicic esters of alcohols of theabovementioned type which contain twelve to twenty carbon atoms haveproved to be very good;

atent esters of alcohols containing fourteen to eighteen carbon atomsare preferred.

Examples of alcohols from which tetrasilicic esters in accordance withthis invention are derived are n-hexadecenyl alcohol, oleyl alcohol,elaidyl alcohol, eicosenyl alcohol, linoleyl alcohol and linolenylalcohol. Alcohols with single unsaturation are preferred. Thetetrasilicic esters may be prepared from individual fatty alcohols orfrom mixtures of long-chain unsaturated fatty alcohols with one anotheror with long-chain saturated fatty alcohols, the content of unsaturatedalcohol in the mixture in the latter case being at least so large thatthe mixture has at least the iodine number given above. For examplealcohol mixtures having an iodine number of from 40 to 140 have provedto be very good; mixtures having an iodine number of 40 to arepreferred. Examples of saturated long-chain fatty alcohols which may beused in the alcohol mixtures are lauryl alcohol, n-tridecyl alcohol,myristyl alcohol, cetyl alcohol, n-heptadecyl alcohol, stearyl alcoholand arachidyl alcohol.

The tetrasilicic esters may be prepared by conventional methods, forexample by reaction of silicon tetrachloride with the alcohols oralcohol mixtures at elevated temperature, if desired in indifferentsolvents.

Tetrasilicic esters which contain only so small an amount of unreactedfatty alcohols that they have a hydroxyl number of not more than 5 areparticularly advantageous for the purposes of the present invention.

The new tetrasilicic esters may be applied to the material being treatedby various methods, for example in the form of their solutions inorganic solvents, such as benzene, carbon tetrachloride, kerosine orother petroleum fractions. For reasons of economy and to minimize therisk of fire however it is preferred to use aqueous emulsions. Thoseesters which have a hydroxyl number of not more than 5 are particularlysuitable for this type of application because their concentrated stockemulsions (unlike those of esters having higher hydroxyl numbers) do nottend to become thick and therefore unusable after prolonged storage. Theconcentrated stock emulsions may contain the tetrasilicic esters inamounts of up to 502% by Weight or more. Stock emulsions containingabout 40% by weight of tetrasilicic esters have proved to be verysuitable.

Examples of emulsifiers which the emulsions may contain are anionicsurfactants, particularly alkylsulfonates such as sodiumoctadecanesulfonate, or alkylarylsulfonates, such as sodiumdibutylnaphthalenesulfonate and diethanolaminehexadecylbenzenesulfonate, or nonionic surfactants, particularlyoxyalkylation products, such as the adducts of 2 moles of ethylene oxideto 1 mole of coconut fatty alcohol, of 6 moles of ethylene oxide to 1mole of octadecyl alcohol, of 6 moles of ethylene oxide to 1 mole ofstearic acid and of 40 moles of ethylene oxide to 1 mole of castor oil.Emulsions which contain, as emulsifiers, adducts of at least 20* moles,preferably 20 to 50 moles, of ethylene oxide to 1 mole of fatty alcoholscontaining twelve to twenty carbon atoms, such as sperm oil alcohol,octadecyl alcohol and oleyl alcohol or preferably alkali metal salts ofsulfuric acid hemiesters of these adducts have proved to be particularlysuitable. Emulsions of tetrasilicic esters which remain stable forseveral weeks can be prepared by means of these preferred emulsifiers.The emulsifiers are used in conventional amounts, i.e. in general inamounts of 2 to 6% on the silicic ester.

The stability of the silicic acid emulsions may be further increased byother additives. Thus it has been found that emulsions which containwater-miscible, low molecular weight organic solvents, such as acetone,methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol,tert.-butyl alcohol or mixtures of the same as additives to increasestability are particularly suitable. The solvents not only improve thestability of the emulsions in storage so that they remain unchanged formonths, but they also prevent foam formation in use and increase froststability to such an extent that such emulsions may be frozen and thawedagain without any change in structure. The organic solvents may bepresent in the emulsions for example in amounts of 5 to 20%, preferablyto with reference to the total weight of the emulsion; below 5% theeffect declines markedly, whereas amounts of more than in general do notadd any other advantage. Another greatly recommended possibility forimproving the stability of the emulsions consists in adding urea.Amounts of urea of 2 to 5%, with reference to the weight of silicicester, are adequate. Urea may also be present in the emulsions togetherwith the abovementioned solvents.

To prevent hydrolytic cleavage of the silicic ester it is advisable tobe sure that the emulsions do not contain any free acid and if necessaryto neutralize them with alkaline substances, such as alkali metalhydroxides or ammonia.

The solutions and emulsions of the new silicic esters may be used in thesame way as prior art solutions and emulsions of silicic esters. Forexample the textile material to be treated may be impregnated with themalone by dipping or spraying, then squeezed in the usual Way and driedat room or elevated temperature up to 150 C. There is also thepossibility for example of applying the silicic ester emulsions togetherwith agents which improve crease resistance to the material beingtreated and finishing off the material in the conventional manner.

It has also proved to be suitable to use the solutions or emulsions ofthe silicic esters in a concentration of 10 to 50 grams of ester perliter. With the conventional squeezing conditions used in practice, theamount of pure silicic ester applied is then about 1 to 5% Withreference to the weight of the material being treated.

In these amounts they impart to the textile a pleasant soft handle and aconsiderable improvement in abrasion resistance, tear resistance andsewing properties, without the material acquiring an unpleasant odor.

Any textiles of natural or synthetic fibrous materials of all kinds maybe treated with the new silicic esters, for example those of cotton,rayon staple, rayon, jute, linen. wool, cellulose acetate, linearpolyamides and polyesters and acrylonitrile polymers.

The invention is illustrated by the following Examples; parts andpercentages specified in the examples are by weight. Parts by weightbear the same relation to parts by volume as the kilogram to the liter.

EXAMPLE 1 400 parts of a tetrasilicic ester having a hydroxyl num ber of3 (prepared from silicon tetrachloride and a fatty alcohol mixture(mainly C to C having an iodine number of 40) is heated to 50 C. Thesilicic ester is allowed to flow into a solution (at 50 C.) of 464 partsof water, 110 parts of acetone, 10 parts of urea and 16 parts of thesodium salt of the sulfuric acid hemiester of an adduct of 20 moles ofethylene oxide to 1 mole of octadecyl alcohol while being emulsifiedwith an impeller. The emulsion is homogenised three times at 150atmospheres gauge in a homogenising machine and made neutral with asmall amount of ammonia. The 40% emulsion, which remains stable andmobile for months, is diluted with water to a content of g. of ester perliter. Rayon staple cloth is impregnated with this emulsion on a paddingmachine, squeezed to a 100% liquor pickup and dried at 110 C. on atenter. The cloth has a very soft handle and is free from any unpleasantodor. Equally good results are achieved by using as the emulsifier anadduct of 25 moles of ethylene oxide to 1 mole of octadecyl alcohol.

EXAMPLE 2 400 parts of a tetrasilicic ester having a hydroxyl number of2 which is liquid at room temperature (prepared from silicontetrachloride and a fatty alcohol mixture (C -C having an iodine numberof is allowed to flow While being emulsified with an impeller at roomtemperature into a solution of 444 parts of water, 130 parts ofisopropanol, 10 parts of urea and 16 parts of the sodium salt of thesulfuric acid hemiester of an adduct of 25 moles of ethylene oxide to 1mole of sperm oil alcohol. The pre-emulsion is then homogenised threetimes at 200 atmospheres gauge in a homogenising machine and madeneutral with a small amount of ammonia. It may be kept unchanged forseveral months.

75 parts of this emulsion, 50 parts of N,N-dimethylol- 4,5dihydroxyimidazolidone 2, 40 parts of N,N'-dimethylolbutanediol-l,4-diurethane, 50 parts of 'N,N'-dimethoxymethylurea and 5 parts of monoammonium phosphate are dissolvedin Water to form 1000 parts of finishing liquor. Cotton cloth isimpregnated with this liquor, squeezed to liquor pickup, dried to 8%residual moisture content and heated for three minutes at 145 C.

The cloth has a permanent crease resist finish; it has a very softhandle, high abrasion resistance, high tear resistance and good sewingproperties. It is also free from unpleasant odor.

EXAMPLE 3 50 parts of the tetrasilicic ester specified in Example 2 and3 parts of sodium octadecanesulfonate are dispersed in 948 parts ofWater with an impeller. To destroy the foam formed, 0.25 part oftriisobutyl phosphate is stirred into the emulsion. The emulsionobtained is used to impregnate a cotton cloth which is squeezed to 100%liquor pickup and dried on a tenter at C. The cloth has a very softhandle and is free from unpleasant odor.

EXAMPLE 4 25 parts of the tetrasilicic ester specified in Example 1 isdissolved in 1000 parts by volume of trichloroethylene. Cotton cloth isimpregnated with this solution, squeezed and dried. The fabric has afine silky handle without having acquired an unpleasant odor.

EXAMPLE 5 400 parts of the tetrasilicic ester of sperm oil alcohol isallowed to flow, while being emulsified with an impeller, into asolution of 454 parts of water, parts of ethanol, 10 parts of urea and16 parts of an adduct of 30 moles of ethylene oxide to 1 mole of oleylalcohol. The emulsion formed is homogenised gauge three times at 200atmospheres in a homogenising machine. It is stable for several months.

The sperm oil alcohol used for the preparation of the ester is a mixtureof monounsaturated fatty alcohols having twelve, fourteen, sixteen,eighteen and twenty carbon atoms and saturated fatty alcohols havingtwelve, fourteen, sixteen and eighteen carbon atoms in such a ratio thatthe iodine number is between 80 and 90.

A very similar emulsion is obtained by using the same amount of thetetrasilicic ester of oleyl alcohol instead of the sperm oil alcoholester.

Both emulsions may be used as described in Example 1 with the resultsgiven therein.

We claim:

1. A tetrasilicic ester of a mixture of saturated and unsaturated fattyalcohols having twelve to twenty carbon atoms, said mixture having aniodine number of 40 to 90.

2. A tetrasilicic ester as claimed in claim 1, wherein said alcohols aresperm oil alcohols comprising a mixture of monounsaturated fattyalcohols having twelve, fourteen, sixteen, eighteen and twenty carbonatoms and saturated fatty alcohols having twelve, fourteen, sixteen andeighteen carbon atoms in such a ratio that the iodine number is between80 and 90.

References Cited UNITED STATES PATENTS OTHER REFERENCES Falkenburg eta1.: I.A.C.S., 69, March 1947, pp. 486- TOBIAS E. LEVOW, PrimaryExaminer P. F. SHAVER, Assistant Examiner U.S. Cl. X.R.

